Hello, I'm looking for a laser well suited to popping balloons. I'm in charge of planning a large set of science demonstrations for 1000+ students, and I think popping a bunch of balloons would be a nice project.

It's a large outdoor area, so I was thinking it would be even more fun to use balloons filled with hydrogen or methane.

What wavelengths and Wattages would be best for this? Can anyone recommend a good laser to buy? I'd like something with a tripod mount, and I'll keep everyone far away from it. Should I get a pair of laser goggles too?

300 hundred is enough you need a green 125mW + real power laser that is focusable and the balloons need to be dark blue or black ,don't point at anything except balloons a laserer brand laser is good but there are plenty of other brands that will do the job, not sure if the methane will explode or pop probably but having never done it not sure

You could get a clear balloon and blacken a match tip and suspend the match in the helium filled balloon and set the match alight igniting the helium. Have a look in the companies section for a review on where to buy

You could get a clear balloon and blacken a match tip and suspend the match in the helium filled balloon and set the match alight igniting the helium. Have a look in the companies section for a review on where to buy

Helium is a noble gas and is not flammable. I think you meant hydrogen.

Also, I would recommend buying from this forum, in the Buy Sell Trade section, as I think the best quality lasers are sold here, with great customer service too. I recommend the users Blord and ApexProxy. Their lasers are all very high quality.

If you just want a laser that will pop balloons and doesn't have too much power, try getting one of those 100mW - 150mW Optotronics pointers. Optotronics Green Pen Pointers
However, these are still powerful enough to blind you.

Lasers that pop balloons are all fairly high powered. They can blind you instantly. Please read up the safety section of this forum, and how to handle the lasers properly and how to protect your own eyes and the eyes of others.

ApexProxy's 1.8 W blue lasers look great for the price, but frankly I'm afraid of that much power. Is it even feasible to do an outdoor balloon pop without blinding spectators from reflections? I was thinking the balloons would be 5-10 meters up.

I should mention I don't need a pointer form factor. It will be mounted to a tripod for safety, and I don't want anyone mistaking it for a toy. Naturally I'll keep it locked up, but I'm still wary. It's hard to add external power interlocks too.

It is wise to be afraid of so much power... so am I. The price tag on extremely powerful blues is very low and I still am hesitant to get one.

A balloon pop sounds feasible, but balloons still do reflect light whether they are black or not (and you may need a very powerful laser, depending on how far they are away from the laser). I would recommend getting a matte colored black balloon to lower this drastically. Else, try something like this:

The laser would be placed behind the balloons with the crowd in front so that any reflection would be deflected down, back, or to the sides. (My original drawing failed so I made a picture )

Also I would recommend getting some safety goggles so that you can test the demonstration yourself before doing it for the public. You only have one set of eyes!

I dislike power houses used for demonstrations. It's GREAT that you are teaching and I support teaching and learning but in my eyes the only reasonable way to do this would be to get enough safety glasses for everyone and clear the are so the ONLY people watching are those protected. It's a real big problem. Once an eye is damaged it can't always be fixed. You have two an that's it. Your responsible for 2000+ eyes, 10000 fingers, etc. whatever you decide to do needs to be fool proof. That being said I'm sure a watt of 445 should be just what the doctor ordered.

I don't think I can count on crowd control to ensure everyone is standing in the proper location. The venue pretty much has people on all sides.

I'll look into matte black balloons, and do some testing. If nothing else, I can record it and show a video.

Failing the balloon idea, how about an artificial star guide? Meaning, simply point it straight up, and look at the solid beam. Is green the best for this, or is blue pretty good too? I'll have to look into FAA regulations and flight paths, but at least it won't have reflection issues.

I don't think I can count on crowd control to ensure everyone is standing in the proper location. The venue pretty much has people on all sides.

I'll look into matte black balloons, and do some testing. If nothing else, I can record it and show a video.

Failing the balloon idea, how about an artificial star guide? Meaning, simply point it straight up, and look at the solid beam. Is green the best for this, or is blue pretty good too? I'll have to look into FAA regulations and flight paths, but at least it won't have reflection issues.

Green by a long way is the best for this 50mW will be enough and you will not have the problem with needing a hundred pairs of googles.for star gazing.blue will do nearly the same job but you will need ten times the power which makes it ten times more dangerous stick with green 532nm laser pointer for star gazing, still use common sense with the ppl there and any flying aircraft

Would this be a daytime activity? Even matte balloons reflect and they SUCK. The FDA is pretty strict on lasers. You could always have a laser station. Buy a bunch of 405nm diodes in bulk, (100 dollars if done right) an then get a bunch of modules and or make your own. Then order bulk buttons an battery holders, and talk altoids into giving you a BUNCH of free tins. And wallah arts and crafts lasers.

Yes, it will be in the day. I guess that ruins my visible beam idea too. Getting a bunch of blue-violet diodes might be fun though. Another of my plans was to make a bunch of mini laser projectors, using simple transparencies and a single lens to make the image. Maybe even use an LCD for video.

Arts and crafts lasers probably wouldn't work. It's a great idea, but there are too many people, and not enough time.